1. Field of the Invention
The present invention relates to a method and an apparatus for producing a wiring harness used, for example, in an internal wiring of an office automation (OA) equipment, a home electric appliance or an automotive vehicle.
2. Description of the Prior Art
A known wiring harness for electrical connection arranged in an OA equipment, a home electric appliance or an automotive vehicle is, for example, constructed such that a plurality of wires 1 for connecting a CPU, a display device and a variety of switches are bundled as shown in FIG. 28. The wiring harness of this type is produced by mounting fittings and/or jigs for holding a connector 3 and wires 1 on a flat plate in accordance with an actual wiring path. The wires 1 then are arranged manually on the jigs, and an adhesive tape 2 then is wound for protection around a bundle of wires 1. The wire bundle then is covered with an unillustrated resin-molded casing to hold it in a specified configuration, and the cased wire bundle is mounted so as to conform to a wiring path inside an OA equipment, a home electric appliance, an automotive vehicle or the like (first prior art). However, according to this prior art, it takes a large amount of time to wind the adhesive tape 2 after the arrangement of the wire bundle on the jigs, thereby lowering a work efficiency.
There are also known flat cables having a multitude of contacts such as flexible print cables (FPC) in which a pattern of conductive paths 4 is printed on a flexible base film 5 which is then overlaid with a cover film 6, as shown in FIGS. 29 and 30. However, in the case of a complicated wiring harness having curved conductive paths 4, an etching mask is applied for each pattern in a production process, and after the patterns are formed in a large base film Dk, a patterned portion is punched and cut off as shown in FIG. 30. Thus, large apparatuses such as an etching apparatus and a cutting apparatus are required. Further, the use of the large base film Dk necessitates a large work space, leading to a poor space efficiency.
Further, as shown in FIG. 31, there is also a known method for linearly arranging a plurality of strip-like conductors 8 in parallel with each other, laying films 5, 6 on the opposite sides of the conductors 8, and folding the thus obtained flat cable according to a wiring path. According to this method, the apparatuses required for the prior art of FIGS. 29 and 30 can be dispensed with. However, in the wiring harness obtained according to this prior art, folded portions 9 may be damaged or a portion between the folded portions 9 may be deformed in such a three-dimensional manner to part from the remaining parts of the wiring harness due to the elastic restoration of the folded portions 9 as shown in FIG. 32. This presents a problem that the configuration of the wiring harness cannot stably conform to the wiring path.
An object of the present invention is to provide a method for easily and efficiently producing a wiring harness using an apparatus having an excellent space efficiency and a simple construction and also to provide such a wiring harness producing apparatus.